Polyorganosiloxane latex, graft copolymer using the same, thermoplastic resin composition, and molded body

Abstract

A variety of molded bodies having high weatherability, impact resistance, designability, and the like, and a polyorganosiloxane latex and a graft copolymer used as the raw materials therefor are provided, where the polyorganosiloxane latex has a mass average particle diameter (Dw) of a polyorganosiloxane particle of 100 to 200 nm, and a ratio of the mass average particle diameter (Dw) to a number average particle diameter (Dn) (Dw/Dn) of 1.0 to 1.7. A polyorganosiloxane-containing vinyl-based copolymer (g) obtained by polymerizing one or more vinyl-based monomers in the presence of the latex. A graft copolymer (G) is obtained by graft polymerizing one or more vinyl-based monomers in the presence of the copolymer. A thermoplastic resin composition includes the graft copolymer (G) and a thermoplastic resin (Ha) except for the graft copolymer (G). A molded body is obtained by molding the resin composition.

The invention claimed is: 
     
       1. A method of preparing a polyorganosiloxane latex, where a polyorganosiloxane particle of the latex has a mass average particle diameter (Dw) of 100 to 200 nm, and where a ratio (Dw/Dn) of the mass average particle diameter (Dw) to a number average particle diameter (Dn) is 1.0 to 1.7, the method comprising:
 dropping an emulsion (B) comprising an organosiloxane, an emulsifier, and water into a water-based medium (A) comprising water, an organic acid catalyst, and an inorganic acid catalyst; and 
 polymerizing the organosiloxane, 
 
       wherein:
 a total amount of the organic acid catalyst and the emulsifier is 0.5 to 6 parts by mass based on 100 parts by mass of the organosiloxane, 
 the water-based medium (A) is at a pH within the range of 0 to 1.2 when measured at 25° C., and 
 the dropping of the emulsion (B) is at a rate such that an amount of the organosiloxane fed is 0.5 parts by mass/min or less when a total amount of the organosiloxane to be used is 100 parts by mass. 
 
     
     
       2. The method according to  claim 1 , wherein a standard deviation of the mass average particle diameter (Dw) of the polyorganosiloxane particle is 0 to 80. 
     
     
       3. The method according to  claim 1 , wherein a proportion of the polyorganosiloxane particles having a particle diameter of less than 50 nm is 5% by mass or less based on the total amount of the particles, and wherein a proportion of the polyorganosiloxane particles having a particle diameter of 300 nm or more is 20% by mass or less based on the total amount of the particles. 
     
     
       4. The method according to  claim 1 , wherein the polyorganosiloxane particle has a mass average particle diameter (Dw) of 100 to 190 nm. 
     
     
       5. A method of preparing a polyorganosiloxane-containing vinyl-based copolymer comprising:
 preparing by the method according to  claim 1  the polyorganosiloxane latex, and 
 polymerizing one or more vinyl-based monomers in the presence of the polyorganosiloxane latex. 
 
     
     
       6. The method of  claim 5 , where a particle of the polyorganosiloxane-containing vinyl-based copolymer has a mass average particle diameter (Dw) of 110 nm to 800 nm, and a ratio (Dw/Dn) of the mass average particle diameter (Dw) to a number average particle diameter (Dn) is 1.0 to 2.0. 
     
     
       7. The method of  claim 5 , wherein the vinyl-based monomer is an acrylic acid ester.